1. Field of the Invention
The present invention relates to a circuit interrupter such as a self-arc extinction type circuit interrupter in which high pressure fluid e.g. SF.sub.6 gas whose pressure is raised by the arc formed between contacts, is used for performing the arc extinction.
2. Description of the Prior Arts
In the conventional circuit interrupters, a fluid in a suitable volumetric space is pressurized by the pressurizing function of arc energy transmitted from the arc to the fluid filled in the space and the pressurized fluid is released from an opening closed by the arc through the arc spacer under periodical changes of the arc current decreasing it to zero and the arc extinction is attained by the resulting puffing effect and cooling effect.
In such self-arc extinction type circuit interrupter, it is important to provide directly or indirectly the pressurized fluid source by the pressurizing function. The function of the arc extinction is highly affected depending upon the means for providing the pressurized fluid. The function for forming the pressurized fluid source for a short time is the most important and indispensable function for the power of the arc extinction and it is the indispensable factor for a circuit interrupter having a short arcing time.
In general, the pressurized fluid source is provided by the pressurizing function of the arc heat energy in the self-arc extinction type circuit interrupter. In order to obtain a desired pressurizing function, it is necessary to control the arc energy as the source of the pressurizing function.